PTP: add support for one-shot output

Some controllers allow for a one-shot output pulse, in contrast to
periodic output. Now that we have extensible versions of our IOCTLs, we
can finally make use of the 'flags' field to pass a bit telling driver
that if we want one-shot pulse output.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Reviewed-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/ptp_clock.h

@@ -38,8 +38,8 @@
 /*
  * Bits of the ptp_perout_request.flags field:
  */
-#define PTP_PEROUT_VALID_FLAGS (0)
-
+#define PTP_PEROUT_ONE_SHOT (1<<0)
+#define PTP_PEROUT_VALID_FLAGS	(PTP_PEROUT_ONE_SHOT)
 /*
  * struct ptp_clock_time - represents a time value
  *
@@ -77,7 +77,7 @@ struct ptp_perout_request {
 	struct ptp_clock_time start;  /* Absolute start time. */
 	struct ptp_clock_time period; /* Desired period, zero means disable. */
 	unsigned int index;           /* Which channel to configure. */
-	unsigned int flags;           /* Reserved for future use. */
+	unsigned int flags;
 	unsigned int rsv[4];          /* Reserved for future use. */
 };